This invention relates generally to a fluid dispenser having a reciprocable pump plunger, and more particularly to a frangible strap engaging the plunger for preventing its reciprocation during initial periods of non-use.
Plunger lock-down for the class of dispensers to which the invention is directed have included a threaded coupling between the plunger and its cylinder for selectively immobilizing the plunger in its fully depressed condition during shipping and/or storage. Such plunger immobilization is disclosed, for example, by U.S. Pat. No. 3,216,625.
Protective overcaps have also been utilized for this class of dispensers to immobilize plunger reciprocation during periods of non-use. And, U.S. Pat. No. 3,403,823 discloses a tamper-proof actuator cap which comprises an actuator button and a base portion with frangible joining means between the button structure and the base so as to enable separation in response to the application of a downward operating force on the button prior to the dispensing operation.
All of these various approaches taken for immobilizing the plunger are, however, somewhat cumbersome, unrealiable and/or costly, so that a more reliable, less costly, less cumbersome and more appealing approach as taken by the invention is desirable.